/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.mpp.common.schematree.visitor;

import org.apache.iotdb.commons.path.MeasurementPath;
import org.apache.iotdb.commons.path.PartialPath;
import org.apache.iotdb.commons.path.fa.IFAState;
import org.apache.iotdb.commons.path.fa.IFATransition;
import org.apache.iotdb.db.mpp.common.schematree.node.SchemaNode;

import java.util.Map;

public class SchemaTreeMeasurementVisitor extends SchemaTreeVisitor<MeasurementPath> {

    private final String tailNode;

    public SchemaTreeMeasurementVisitor(
            SchemaNode root, PartialPath pathPattern, int slimit, int soffset, boolean isPrefixMatch) {
        super(root, pathPattern, slimit, soffset, isPrefixMatch);
        tailNode = pathPattern.getTailNode();
    }

    @Override
    protected IFAState tryGetNextState(
            SchemaNode node, IFAState sourceState, Map<String, IFATransition> preciseMatchTransitionMap) {
        IFATransition transition;
        IFAState state;
        if (node.isMeasurement()) {
            String alias = node.getAsMeasurementNode().getAlias();
            if (alias != null) {
                transition = preciseMatchTransitionMap.get(alias);
                if (transition != null) {
                    state = patternFA.getNextState(sourceState, transition);
                    if (state.isFinal()) {
                        return state;
                    }
                }
            }
            transition = preciseMatchTransitionMap.get(node.getName());
            if (transition != null) {
                state = patternFA.getNextState(sourceState, transition);
                if (state.isFinal()) {
                    return state;
                }
            }
            return null;
        }

        transition = preciseMatchTransitionMap.get(node.getName());
        if (transition == null) {
            return null;
        }
        return patternFA.getNextState(sourceState, transition);
    }

    @Override
    protected IFAState tryGetNextState(
            SchemaNode node, IFAState sourceState, IFATransition transition) {
        IFAState state;
        if (node.isMeasurement()) {
            String alias = node.getAsMeasurementNode().getAlias();
            if (alias != null && transition.isMatch(alias)) {
                state = patternFA.getNextState(sourceState, transition);
                if (state.isFinal()) {
                    return state;
                }
            }
            if (transition.isMatch(node.getName())) {
                state = patternFA.getNextState(sourceState, transition);
                if (state.isFinal()) {
                    return state;
                }
            }
            return null;
        }

        if (transition.isMatch(node.getName())) {
            return patternFA.getNextState(sourceState, transition);
        }
        return null;
    }

    @Override
    protected boolean processInternalMatchedNode(SchemaNode node) {
        return true;
    }

    @Override
    protected boolean processFullMatchedNode(SchemaNode node) {
        if (node.isMeasurement()) {
            nextMatchedNode = node;
            return false;
        }
        return true;
    }

    @Override
    protected MeasurementPath generateResult() {
        MeasurementPath result =
                new MeasurementPath(
                        generateFullPathNodes(), nextMatchedNode.getAsMeasurementNode().getSchema());
        result.setTagMap(nextMatchedNode.getAsMeasurementNode().getTagMap());
        result.setUnderAlignedEntity(getParentOfNextMatchedNode().getAsEntityNode().isAligned());
        String alias = nextMatchedNode.getAsMeasurementNode().getAlias();
        if (tailNode.equals(alias)) {
            result.setMeasurementAlias(alias);
        }

        return result;
    }
}
